anechoic chamber

While a darkroom is a space isolated from external light, an anechoic chamber is a space isolated from external electromagnetic waves. Anechoic chambers are designed to block electromagnetic waves from the outside, prevent internally generated waves from leaking out, and their walls are made of materials that absorb rather than reflect electromagnetic waves. Anechoic chambers are used for testing the electromagnetic compatibility (EMC) of electrical and electronic equipment, as well as for testing wireless devices.